"""
Test Suite for Auth Service

Comprehensive tests for the authentication service including:
- JWT token creation and verification
- Token expiry validation
- Token version checking (logout/invalidation)
- Google OAuth token verification (mocked)
- Error handling
"""

import pytest
import os
from datetime import datetime, timedelta
from unittest.mock import patch, MagicMock

from services.auth_service.jwt_provider import (
    JWTService,
    TokenPayload,
    create_access_token,
    create_refresh_token,
    verify_access_token,
    TokenExpiredError,
    InvalidTokenError,
    ConfigurationError,
    get_jwt_service
)
from services.auth_service.google_provider import (
    GoogleAuthService,
    GoogleUserInfo,
    InvalidTokenError as GoogleInvalidTokenError,
    ConfigurationError as GoogleConfigError,
    get_google_auth_service
)


# ============================================================================
# Fixtures
# ============================================================================

@pytest.fixture
def jwt_secret():
    """Provide a test JWT secret."""
    return "test-secret-key-for-testing-only-do-not-use-in-production"


@pytest.fixture
def jwt_service(jwt_secret):
    """Create a JWTService instance for testing."""
    return JWTService(
        secret_key=jwt_secret,
        algorithm="HS256",
        access_expiry_minutes=15,
        refresh_expiry_days=7
    )


@pytest.fixture
def google_client_id():
    """Provide a test Google client ID."""
    return "test-google-client-id.apps.googleusercontent.com"


@pytest.fixture
def mock_google_user_info():
    """Provide mock Google user info."""
    return GoogleUserInfo(
        google_id="12345678901234567890",
        email="test@example.com",
        name="Test User",
        picture="https://example.com/photo.jpg"
    )


# ============================================================================
# JWT Service Tests
# ============================================================================

class TestJWTService:
    """Test JWT token creation and verification."""
    
    def test_service_initialization(self, jwt_secret):
        """Test that JWT service initializes correctly."""
        service = JWTService(
            secret_key=jwt_secret,
            algorithm="HS256",
            access_expiry_minutes=15,
            refresh_expiry_days=7
        )
        
        assert service.secret_key == jwt_secret
        assert service.algorithm == "HS256"
        assert service.access_expiry_minutes == 15
        assert service.refresh_expiry_days == 7
    
    def test_service_requires_secret(self, monkeypatch):
        """Test that service requires a secret key."""
        # Clear environment variable so it can't fall back to env
        monkeypatch.delenv("JWT_SECRET", raising=False)
        
        with pytest.raises(ConfigurationError) as exc_info:
            JWTService(secret_key=None)  # None and no env var
        
        assert "secret" in str(exc_info.value).lower()
    
    def test_service_warns_short_secret(self, caplog):
        """Test that service warns about short secret keys."""
        short_secret = "short"
        service = JWTService(secret_key=short_secret)
        
        assert "short" in caplog.text.lower() or "32 chars" in caplog.text.lower()
    
    def test_service_from_env(self, monkeypatch, jwt_secret):
        """Test that service reads config from environment."""
        monkeypatch.setenv("JWT_SECRET", jwt_secret)
        monkeypatch.setenv("JWT_ALGORITHM", "HS512")
        monkeypatch.setenv("JWT_ACCESS_EXPIRY_MINUTES", "30")
        monkeypatch.setenv("JWT_REFRESH_EXPIRY_DAYS", "14")
        
        service = JWTService()
        
        assert service.secret_key == jwt_secret
        assert service.algorithm == "HS512"
        assert service.access_expiry_minutes == 30
        assert service.refresh_expiry_days == 14


class TestAccessTokenCreation:
    """Test access token creation."""
    
    def test_create_access_token(self, jwt_service):
        """Test creating an access token."""
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com",
            token_version=1
        )
        
        assert isinstance(token, str)
        assert len(token) > 0
        assert token.count('.') == 2  # JWT format: header.payload.signature
    
    def test_access_token_payload(self, jwt_service):
        """Test that access token has correct payload."""
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com",
            token_version=1
        )
        
        payload = jwt_service.verify_token(token)
        
        assert payload.user_id == "usr_123"
        assert payload.email == "test@example.com"
        assert payload.token_version == 1
        assert payload.token_type == "access"
    
    def test_access_token_expiry(self, jwt_service):
        """Test that access token has correct expiry time."""
        before = datetime.utcnow()
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com"
        )
        after = datetime.utcnow()
        
        payload = jwt_service.verify_token(token)
        
        # Should expire 15 minutes from creation (with some tolerance for execution time)
        expected_min = before + timedelta(minutes=15) - timedelta(seconds=1)
        expected_max = after + timedelta(minutes=15) + timedelta(seconds=1)
        
        assert expected_min <= payload.expires_at <= expected_max
    
    def test_access_token_custom_expiry(self, jwt_service):
        """Test creating token with custom expiry."""
        custom_delta = timedelta(hours=1)
        token = jwt_service.create_token(
            user_id="usr_123",
            email="test@example.com",
            token_type="access",
            expiry_delta=custom_delta
        )
        
        payload = jwt_service.verify_token(token)
        time_diff = payload.expires_at - payload.issued_at
        
        # Should be approximately 1 hour
        assert 3590 <= time_diff.total_seconds() <= 3610
    
    def test_access_token_extra_claims(self, jwt_service):
        """Test creating token with extra claims."""
        token = jwt_service.create_token(
            user_id="usr_123",
            email="test@example.com",
            token_type="access",
            extra_claims={"role": "admin", "org": "test_org"}
        )
        
        payload = jwt_service.verify_token(token)
        
        assert payload.extra.get("role") == "admin"
        assert payload.extra.get("org") == "test_org"


class TestRefreshTokenCreation:
    """Test refresh token creation."""
    
    def test_create_refresh_token(self, jwt_service):
        """Test creating a refresh token."""
        token = jwt_service.create_refresh_token(
            user_id="usr_123",
            email="test@example.com",
            token_version=1
        )
        
        assert isinstance(token, str)
        assert len(token) > 0
    
    def test_refresh_token_type(self, jwt_service):
        """Test that refresh token has correct type."""
        token = jwt_service.create_refresh_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        payload = jwt_service.verify_token(token)
        
        assert payload.token_type == "refresh"
    
    def test_refresh_token_longer_expiry(self, jwt_service):
        """Test that refresh token expires in 7 days."""
        before = datetime.utcnow()
        token = jwt_service.create_refresh_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        payload = jwt_service.verify_token(token)
        time_diff = payload.expires_at - before
        
        # Should be approximately 7 days
        expected_seconds = 7 * 24 * 60 * 60
        assert abs(time_diff.total_seconds() - expected_seconds) < 10


class TestTokenVerification:
    """Test token verification."""
    
    def test_verify_valid_token(self, jwt_service):
        """Test verifying a valid token."""
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        payload = jwt_service.verify_token(token)
        
        assert payload.user_id == "usr_123"
        assert payload.email == "test@example.com"
    
    def test_verify_empty_token(self, jwt_service):
        """Test that empty token raises error."""
        with pytest.raises(InvalidTokenError) as exc_info:
            jwt_service.verify_token("")
        
        assert "empty" in str(exc_info.value).lower()
    
    def test_verify_malformed_token(self, jwt_service):
        """Test that malformed token raises error."""
        with pytest.raises(InvalidTokenError):
            jwt_service.verify_token("not.a.valid.jwt.token")
    
    def test_verify_tampered_token(self, jwt_service):
        """Test that tampered token raises error."""
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        # Tamper with the token
        parts = token.split('.')
        parts[1] = parts[1][:-5] + "AAAAA"  # Change payload
        tampered = '.'.join(parts)
        
        with pytest.raises(InvalidTokenError):
            jwt_service.verify_token(tampered)
    
    def test_verify_token_wrong_secret(self, jwt_service):
        """Test that token with wrong secret fails."""
        # Create token with one secret
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        # Try to verify with different secret
        wrong_service = JWTService(secret_key="different-secret")
        
        with pytest.raises(InvalidTokenError):
            wrong_service.verify_token(token)


class TestTokenExpiry:
    """Test token expiry behavior."""
    
    def test_expired_token_raises_error(self, jwt_service):
        """Test that expired token raises TokenExpiredError."""
        # Create token that expires immediately
        token = jwt_service.create_token(
            user_id="usr_123",
            email="test@example.com",
            token_type="access",
            expiry_delta=timedelta(seconds=-1)  # Already expired
        )
        
        with pytest.raises(TokenExpiredError) as exc_info:
            jwt_service.verify_token(token)
        
        assert "expired" in str(exc_info.value).lower()
    
    def test_token_not_expired_yet(self, jwt_service):
        """Test that non-expired token verifies successfully."""
        token = jwt_service.create_token(
            user_id="usr_123",
            email="test@example.com",
            token_type="access",
            expiry_delta=timedelta(hours=1)
        )
        
        # Should not raise
        payload = jwt_service.verify_token(token)
        assert payload.user_id == "usr_123"
        assert not payload.is_expired
    
    def test_token_expiry_property(self, jwt_service):
        """Test TokenPayload.is_expired property."""
        token = jwt_service.create_token(
            user_id="usr_123",
            email="test@example.com",
            expiry_delta=timedelta(seconds=-1)
        )
        
        # Decode without verifying expiry
        import jwt as pyjwt
        payload_dict = pyjwt.decode(
            token,
            jwt_service.secret_key,
            algorithms=[jwt_service.algorithm],
            options={"verify_exp": False}
        )
        
        payload = TokenPayload(
            user_id=payload_dict["sub"],
            email=payload_dict["email"],
            issued_at=datetime.utcfromtimestamp(payload_dict["iat"]),
            expires_at=datetime.utcfromtimestamp(payload_dict["exp"]),
            token_version=payload_dict.get("tv", 1),
            token_type=payload_dict.get("type", "access")
        )
        
        assert payload.is_expired is True


class TestTokenVersion:
    """Test token version functionality."""
    
    def test_token_version_in_payload(self, jwt_service):
        """Test that token version is included in payload."""
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com",
            token_version=5
        )
        
        payload = jwt_service.verify_token(token)
        
        assert payload.token_version == 5
    
    def test_default_token_version(self, jwt_service):
        """Test that default token version is 1."""
        token = jwt_service.create_access_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        payload = jwt_service.verify_token(token)
        
        assert payload.token_version == 1


class TestConvenienceFunctions:
    """Test module-level convenience functions."""
    
    def test_create_access_token_function(self, monkeypatch, jwt_secret):
        """Test create_access_token convenience function."""
        monkeypatch.setenv("JWT_SECRET", jwt_secret)
        
        # Reset singleton
        import services.auth_service.jwt_provider as jwt_module
        jwt_module._default_service = None
        
        token = create_access_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        assert isinstance(token, str)
        assert len(token) > 0
    
    def test_create_refresh_token_function(self, monkeypatch, jwt_secret):
        """Test create_refresh_token convenience function."""
        monkeypatch.setenv("JWT_SECRET", jwt_secret)
        
        # Reset singleton
        import services.auth_service.jwt_provider as jwt_module
        jwt_module._default_service = None
        
        token = create_refresh_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        assert isinstance(token, str)
        payload_dict = jwt_module.get_jwt_service().verify_token(token)
        assert payload_dict.token_type == "refresh"
    
    def test_verify_access_token_function(self, monkeypatch, jwt_secret):
        """Test verify_access_token convenience function."""
        monkeypatch.setenv("JWT_SECRET", jwt_secret)
        
        # Reset singleton
        import services.auth_service.jwt_provider as jwt_module
        jwt_module._default_service = None
        
        token = create_access_token(
            user_id="usr_123",
            email="test@example.com"
        )
        
        payload = verify_access_token(token)
        
        assert payload.user_id == "usr_123"
    
    def test_get_jwt_service_singleton(self, monkeypatch, jwt_secret):
        """Test that get_jwt_service returns singleton."""
        monkeypatch.setenv("JWT_SECRET", jwt_secret)
        
        # Reset singleton
        import services.auth_service.jwt_provider as jwt_module
        jwt_module._default_service = None
        
        service1 = get_jwt_service()
        service2 = get_jwt_service()
        
        assert service1 is service2  # Same instance


# ============================================================================
# Google OAuth Tests
# ============================================================================

class TestGoogleAuthService:
    """Test Google OAuth integration."""
    
    def test_service_initialization(self, google_client_id):
        """Test Google auth service initialization."""
        service = GoogleAuthService(client_id=google_client_id)
        
        assert service.client_id == google_client_id
    
    def test_service_requires_client_id(self, monkeypatch):
        """Test that service requires client ID."""
        # Clear environment variable so it can't fall back to env
        monkeypatch.delenv("AUTH_SIGN_IN_GOOGLE_CLIENT_ID", raising=False)
        monkeypatch.delenv("GOOGLE_CLIENT_ID", raising=False)
        
        with pytest.raises(GoogleConfigError) as exc_info:
            GoogleAuthService(client_id=None)  # None and no env var
        
        assert "client id" in str(exc_info.value).lower()
    
    @patch('google.oauth2.id_token.verify_oauth2_token')
    def test_verify_valid_token(self, mock_verify, google_client_id, mock_google_user_info):
        """Test verifying valid Google ID token."""
        # Mock the Google verification
        mock_verify.return_value = {
            'sub': mock_google_user_info.google_id,
            'email': mock_google_user_info.email,
            'name': mock_google_user_info.name,
            'picture': mock_google_user_info.picture,
            'iss': 'accounts.google.com',
            'aud': google_client_id
        }
        
        service = GoogleAuthService(client_id=google_client_id)
        user_info = service.verify_token("fake-google-id-token")
        
        assert user_info.google_id == mock_google_user_info.google_id
        assert user_info.email == mock_google_user_info.email
        assert user_info.name == mock_google_user_info.name
        assert user_info.picture == mock_google_user_info.picture
    
    @patch('google.oauth2.id_token.verify_oauth2_token')
    def test_verify_invalid_token(self, mock_verify, google_client_id):
        """Test that invalid token raises error."""
        # Mock verification failure
        mock_verify.side_effect = ValueError("Invalid token")
        
        service = GoogleAuthService(client_id=google_client_id)
        
        with pytest.raises(GoogleInvalidTokenError) as exc_info:
            service.verify_token("invalid-token")
        
        assert "invalid" in str(exc_info.value).lower()
    
    @patch('google.oauth2.id_token.verify_oauth2_token')
    def test_verify_wrong_audience(self, mock_verify, google_client_id):
        """Test that token with wrong audience fails."""
        # Mock token with wrong audience
        mock_verify.return_value = {
            'sub': '12345',
            'email': 'test@example.com',
            'iss': 'accounts.google.com',
            'aud': 'wrong-client-id'
        }
        
        service = GoogleAuthService(client_id=google_client_id)
        
        with pytest.raises(GoogleInvalidTokenError):
            service.verify_token("token-for-wrong-app")


# ============================================================================
# Run Tests
# ============================================================================

if __name__ == "__main__":
    pytest.main([__file__, "-v", "--tb=short"])